<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
<label for="pic">
    <img src="1.png" alt="" id="tmp_pic">
</label>
<input type="file" name="pic" id="pic" style="display: none">
<script>
    var pic = document.getElementById('pic');
    var tmp_pic = document.getElementById('tmp_pic');

    pic.onchange = function ()
    {
        var file = this.files[0];
        var fd = new FileReader();
        fd.readAsDataURL(file);
        fd.onload = function ()
        {
            tmp_pic.src = fd.result
        }
    }
</script>
</body>
</html>